"Witnessed observed her forcefully remove the child. her daughter was 4 years old", Tampa Police Chief Brian Dugan said.
Authorities responding to reports of a child thrown into the river found the unconscious girl about 30 minutes later. He said it appears she drove to the bridge, but police couldn't release further details Thursday afternoon as they continue to investigate.
Police spokesman Steve Hegarty told the Times that police arrested the woman after she was found walking close to the scene.
Dugan said Shakayla Denson, 26, stole a vehicle from Jordan Auto Repair on N. 40th Street, a short distance from her apartment, just after 3 p.m. Thursday.
Tampa police say Denson stole a auto Thursday afternoon from a sales lot and forced her daughter inside.
"I live in the building across and I was out on the balcony and I first looked to see if therew as a boat, like perhaps this person's boat had broken down", said Vicki Walker.
Denson has previous arrests for driving with a suspended license and theft charges dating back two years ago.
Je'Hyrah Daniels, 4, was diagnosed with autism.
Neighbor Shantia Little told the Tampa Bay Times that Denson would frequently leave Je'Hyrah and a young niece and nephew alone in her apartment.
"The mom is in custody, and right now we are sorting through to get answers", said Dugan. The investigation was closed Tuesday after no evidence of maltreatment, abuse or neglect was found, the agency said.
On Jan. 8, 2015, 5-year-old Pheobe was thrown off the Dick Misener Bridge into Tampa Bay by her father, John Jonchuck.